The present invention generally relates to appliance and, more particularly, to refrigerators and temperature control for the same.
Up to the present invention, temperature control for refrigerators was done manually. Once the temperature settings of a regulator or computer panel for refrigerators"" temperature control has been determined, temperature values for turning the refrigerator on/off are fixed. The values remain unchanged no matter the ambient temperature has changed. It would be fine in a situation that the ambient temperature is changed in a narrow range. However, if the ambient temperature changes significantly, the fixed values may not keep the temperature in the refrigerator at a required level. As a result, the food in the refrigerator becomes either defrozen as the temperature in the refrigerator is too high or over frozen as the temperature in the refrigerator is too low. Either of both eases is adverse for food reservation.
One objective of the present invention is to provide a temperature control for refrigerators, which may automatically regulate values for turning the refrigerator on/off as the ambient temperature varies.
Another objective of the present invention is to provide a simply designed refrigerator with a reasonably allocated environment sensor.
In accordance with the present invention, a method for temperature control comprises steps of defining at least a first temperature division and a second temperature division of ambient temperature and determining first on-temp/off-temp values for turning on/off the refrigerator in said first temperature division and second on-temp/off-temp values for turning on/off the refrigerator in said second temperature division; detecting and transferring ambient temperature signals to a control processor; enabling the on-temp/off-temp values by the control processor in response to received ambient temperature signals; determining in response to the ambient temperature signals whether variation of the ambient temperature is within the first temperature division and adjusting the first on-temp/off-temp values to the second on-temp/off-temp values if the ambient temperature changes from the first temperature division to the second temperature division.
In accordance with the present invention, the on values corresponding to a plurality of temperature divisions are consistent while the off-temp values are changed. Furthermore, a plurality of temperature division has correspondent on-temp/off-temp values as follows:
The present invention provides a refrigerator comprising a shell and a control processor. A sensor is set up at the rear top of the shell, in particular, a position for separating the cooling source from the heating source. The sensor is coupled to the input of the control processor which outputs are coupled to a heater and a compressor respectively.
In accordance with the present invention, the sensor is connected to a power supply through a resistor and to the input of the control processor through a capacitor The sensor is grounded directly. The input of the control processor is connected to the power supply through a resistor and a capacitor.
Furthermore, the heater is connected across the power supply and in series with the normal-on switch of a relay that is connected in parallel with a diode. The output of the control processor is connected to the base of a transistor through a resistor. The emitter of the transistor is grounded while the collector of the transistor is connected to the power supply.
Moreover, the compressor is connected across the power supply and in series with the normal-on switch of the relay that is connected in parallel with a diode. The output of control processor is connected to the base of the transistor. The emitter of the transistor is grounded while the collector of the transistor is connected to the power supply.
The advantages and essential effects of the invention are that with location of the sensor in the rear shell top of ale refrigerator, neither cooling source nor heating source all around, thereby minimizing the disturbance to the operation of the sensor. In accordance with a preferred embodiment of the present invention, a particular temperature division is determined [21, 28) at ambient temperature of 25xc2x0 C. so the on-temp value should be 4xc2x0 C. and the off-temp value xe2x88x9218xc2x0 C. With these on-temp and off-temp values in this particular division, the temperature of the storage compartment in the refrigerator is maintained within a range of 4xc2x0 C.xcx9c7xc2x0 C. while the temperature of the freezing compartment is stabilized under xe2x88x9218xc2x0 C. When the ambient temperature fluctuates in 21xc2x0 C.xcx9c28xc2x0 C., the on-temp value is still +4xc2x0 C. and the off-temp value of xe2x88x9218xc2x0 C. remains unchanged, so the temperature in the refrigerator keeps unchanged also. When the ambient temperature drops to about +18xc2x0 C., the sensor detects the current temperature and sends a detecting signal to the control processor that determines the current ambient temperature in the temperature division [14, 21), thereby automatically setting up the on-temp value at 4xc2x0 C. and the off-temp value at xe2x88x9219xc2x0 C. Accordingly, the refrigerator operates under such conditions, keeping the temperature in the refrigerator unchanged.